Systems and methods for calculating motor position, inertia and rest position in sensorless brushed DC motor control systems, and for determining seat occupant weight based on motor current
A system includes a motor control module and an occupant weight classification module. The motor control module is configured to supply power to a motor to move a seat in a first direction from a first position to a second position when the seat is unoccupied and supply power to the motor to move the seat in a second direction from a third position to a fourth position when an occupant is in the seat. The occupant weight classification module is configured to measure a first frequency of ripples in current supplied to the motor as the seat is moved from the first position to the second position, measure a second frequency of ripples in the current supplied to the motor as the seat is moved from the third position to the fourth position, and determine a weight of the occupant based on the first and second frequencies.
1. A system comprising:
a motor control module configured to:
supply power to a motor to move a seat in a first direction from a first position to a second position when the seat is unoccupied; and
supply power to the motor to move the seat in a second direction from a third position to a fourth position when an occupant is in the seat; and
an occupant weight classification module configured to:
measure a first frequency of ripples in current supplied to the motor as the seat is moved from the first position to the second position;
measure a second frequency of ripples in the current supplied to the motor as the seat is moved from the third position to the fourth position; and
determine a weight of the occupant based on the first and second frequencies.
2. The system of claim 1 wherein a first distance between the first and second positions is equal to a second distance between the third and fourth positions.
3. The system of claim 1 wherein the second direction is the same as the first direction.
4. The system of claim 1 wherein:
the third position is the same as the first position; and
the fourth position is the same as the second position.
5. The system of claim 1 wherein:
the third position is the same as the second position; and
the fourth position is the same as the first position.
6. The system of claim 1 wherein the occupant weight classification module is configured to determine whether the seat is occupied based on an input from at least one of a seat belt latch sensor, a door latch sensor, and a camera operable to generate an image of the seat.
7. The system of claim 1 wherein the occupant weight classification module is configured to determine the weight of the occupant based on a difference between the first and second frequencies.
8. The system of claim 1 wherein the first and second directions are vertical directions.
9. The system of claim 1 wherein the first direction is a downward direction and the second direction is an upward direction.
10. The system of claim 1 wherein the occupant weight classification module is configured to:
determine a weight of the seat based on the first frequency;
determine a total weight of the seat and the occupant based on the second frequency; and
determine the weight of the occupant by subtracting the weight of the seat from the total weight of the seat and the occupant.
11. A system comprising:
a motor control module configured to:
supply power to a motor to move a seat in a first direction for a first period when the seat is unloaded; and
supply power to the motor to move the seat in a second direction for a second period when an occupant is in the seat; and
an occupant weight classification module configured to:
measure a first number of ripples in current supplied to the motor during the first period;
measure a second number of ripples in the current supplied to the motor during the second period; and
determine a weight of the occupant based on the first number of ripples and the second number of ripples.
12. The system of claim 11 wherein the second period is equal to the first period.
13. The system of claim 11 wherein the second direction is the same as the first direction.
14. The system of claim 11 wherein the occupant weight classification module is configured to determine whether the seat is occupied based on an input from at least one of a seat belt latch sensor, a door latch sensor, and a camera operable to generate an image of the seat.
15. A system comprising:
a motor control module configured to:
supply power to a motor to move a seat in a first direction for a first period when the seat is unloaded; and
supply power to the motor to move the seat in a second direction for a second period when an occupant is in the seat; and
an occupant weight classification module configured to:
measure a first frequency of ripples in current supplied to the motor during the first period;
measure a second frequency of ripples in the current supplied to the motor during the second period; and
determine a weight of the occupant based on the first and second frequencies.
16. The system of claim 15 wherein the second period is equal to the first period.
17. The system of claim 15 wherein the occupant weight classification module is configured to determine the weight of the occupant based on a difference between the first and second frequencies.
18. The system of claim 15 wherein the first and second directions are vertical directions.
19. The system of claim 15 wherein the first direction is a downward direction and the second direction is an upward direction.
20. The system of claim 15 wherein the occupant weight classification module is configured to:
determine a weight of the seat based on the first frequency;
determine a total weight of the seat and the occupant based on the second frequency; and
determine the weight of the occupant by subtracting the weight of the seat from the total weight of the seat and the occupant.